Well I'm not sure if the same thing works on Xbox, I assume it must, but the way to do it on PC is this:

|cB20000This is the text you want coloured!|r (RED)
|cffcc00Your message here!|r (YELLOW)

You need to use hex codes for the colours, pick them from a place like this: http://www.w3schools.com/colors/colors_picker.asp

And you have to have the |r at the end to stop the colour/make it show up.
Give it a try, hopefully it works!

Did you definitely use that vertical bar key?